Constraint Based Geometry

Circles Geometry Expressions is a constraint based geometry system. The benefits of this type of system are:


  • Many geometric configurations are much more easily specified using constraints than constructions
  • It is a much more convenient style for expressing real world problems
  • This is the approach used in modern Computer Aided Design (CAD) systems

Symbolic Geometry

Circles In Geometry Expressions if you put symbols in as the values of constraints, you get symbolic expressions out for measurements (see above figure). This means:
  • Reinforcing multiple representations (geometric and algebraic) of the same problem
  • Symbiosis with CAS (like Maple, Mathematica, Nspire, ClassPad Manager)
  • Makes the geometry software extremely relevant in algebra, precalculus and calculus courses, as well as in university and professional engineering contexts.

Geometry Expressions visualizes and models situations with a few clicks, making the problem more than mere numbers and symbols. This is definitely not the traditional math work that students are accustomed to. It is far more interesting. ”

Ariel Chen
Junior, Westview High School
Portland OR

Latest News

  • We'll be exhibiting at the NCTM Annual Meeting in San Diego, April 21-24. We will be in both number 929.
    At this conference, Philip Todd will talk about "Using Mathematics to Help Cure Hunger, Disease and Global Warming", in Convention Center Room 11B, Thursday April 22nd 12:30 - 1:30. Come join him!

    Cannot come to this conference? No problem, we'll also be exhibiting at USACAS Conference, June 26th-27th. Come see us!

  • We just got a new book from the printer titled: The Farmer and the Mathematician: using Geometry Expressions and Goggle Earth to investigate crop circles, written by Larry Ottman. The lessons in this book utilize images from Google Earth, and a lighthearted scenario of a discussion between a farmer and a mathematician to introduce important mathematical concepts that are appropriate and adaptable for students in a range of courses from Pre-Algebra, Algebra, and Geometry, up through and including Calculus.

  • Geometry Expressions v2.1 and Math Illustrations v1.1 just released recently. New features include:
    1- Figure Gallery
    2- Geometry Atlas
    3- Filled circles and ellipses
    4- Transparency level setting for filled objects
    5- Convenient angle mode switch in the status bar
    6- Objects can be arranged by bringing to front or sending to back
    7- Toggle Hidden mode makes it easy to show/hide objects
    And line rendering is now antialiased on all platforms.